The relationship between self‐annealing of plated copper and copper surface treatment

Circuit World ◽  
2003 ◽  
Vol 29 (3) ◽  
pp. 22-26 ◽  
Author(s):  
Toshiko Nakagawa
Author(s):  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa ◽  
Shogo Matsutani

This report describes the quality assessment of blind via holes (BVHs) of Printed Wiring Boards (PWBs) drilled by a CO2 laser using Cu-direct drilling. In the Cu-direct drilling method, the copper foil and the buildup layer are melted at the same time, and the surface is treated to increase the laser energy absorbed by the copper foil because an untreated copper surface reflects most of the 10.6-μm-wavelength CO2 laser beam. We used black-oxide and V-bond treatments as surface treatment. Previously, the only black-oxide treatment was paid attention to, but the new V-bond treatment is also investigated in this report. First, a straightforward method employing infrared thermography was proposed to determine the absorbance of the CO2 laser beam by the copper surface. Then, we used SEM to characterize the copper surfaces after surface treatment, and established the relationship between laser absorbance and surface shape. Subsequently, we observed the circumference of a point irradiated with the CO2 laser and explained melting processes were different from surface shape. Finally, we investigated the relationship between laser absorbance and BVH quality, and showed that a high absorbance improved BVH quality.


Author(s):  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa ◽  
Tsukasa Ayuzawa

This report describes the quality assessment of Blind Via Holes (BVHs) of Printed Wiring Boards (PWBs) drilled by a CO2 laser using Cu-direct drilling. In the Cu-direct drilling method, the copper foil and the build-up layer are melted at the same time, and the surface is treated to increase the laser energy absorbed by the copper foil since an untreated copper surface reflects most of the 10.6-μm-wavelength CO2 laser beam. However, there are few reports dealing with Cu-direct laser drilling of PWBs. In addition, when copper and resin with different processing thresholds are drilled at the same time, occurrences of a defect called overhang have been observed. So, in this report, first we propose a new method using thermography to measure the absorptance of a PWB surface for a CO2 laser. Moreover, we investigate how surface treatment of the outer copper foil influences the quality of a laser-drilled hole. Then, we observe the circumference of a point irradiated with the CO2 laser and explain how melting processes are different from surface treatment. Finally, based on the research we establish a method in order to cut down the overhang length as a parameter of drilled-hole quality. We also show that a high absorptance improves BVH quality.


1983 ◽  
Vol 105 (1) ◽  
pp. 3-9 ◽  
Author(s):  
M. Sultan ◽  
R. L. Judd

The present investigation is an original study in nucleate pool boiling heat transfer combining theory and experiment in which water boiling at atmospheric pressure on a single copper surface at two different levels of heat and different levels of subcooling was studied. Cross spectral analysis of the signals generated by the emission of bubbles at adjacent nucleation sites was used to determine the relationship of the time elapsed between the start of bubble growth at the two neighbouring active sites with the distance separating them. The experimental results obtained indicated that for the lower level of heat flux at three different levels of subcooling, the elapsed time and distance were directly related. Theoretical predictions of a temperature disturbance propagating through the heating surface in the radial direction gave good agreement with the experimental findings, suggesting that this is the mechanism responsible for the activation of the surrounding nucleation sites.


Circuit World ◽  
1987 ◽  
Vol 14 (1) ◽  
pp. 18-21 ◽  
Author(s):  
H. Akahoshi ◽  
K. Kogawa ◽  
Y. Suzuki ◽  
M. Wajima

2016 ◽  
Vol 8 (3) ◽  
pp. 657
Author(s):  
Jasna Vuković

The problem of the relationship impresso-barbotine has been chosen here, as an excellent example to illustrate the tendencies and shortcomings of the Yugoslav/Serbian archaeology during the major part of the 20th century, as well as the results forming the base for future research and new conclusions. The impresso-barbotine problem has been recognized as one of the important aspects of research into the Early Neolithic as early as in the 1950s, and formed the base for the formation of several relative chronological system. However, although the culture-historical approach is based upon detailed description and stylistic-typological analyses, these phenomena are defined and described in a number of different ways (if at all), causing great confusion. The highly simplified notion about the production and usage of ceramic ware, as well as the negligence for the functional and technological aspects, resulted in the absence of a clear statement if these techniques are in fact a form of decoration or surface treatment. On the other hand, paradoxically, these "elusive" phenomena have been taken as very precise chronological markers. The conclusions are not questionable even today, since the recent research has proven the chronological primacy of impresso over barbotine. Here, however, the shortcomings of the culture- historical method are most obvious: after the establishment of the relative chronological sequence and the identification of a change in the material culture, the reasons that induced the changes are not considered – interpretation is completely absent. However, the current archaeological trends focus upon the processes leading to changes in the material culture, the ones that cannot be explained without considering technology – from forming techniques to modes of usage. Bearing in mind that impresso, and afterwards barbotine appear on the same functional classes of pottery (storage, transportation), it may seem that the same idea motivated both manners of surface treatment – roughening so as to facilitate handling. In order to explain the reasons for the changes it is necessary to consider the forming techniques, with the most reliable indication in the chronological sequence impresso – relief impresso (plastic wheat-grain motif) – barbotine. The production of pottery with uneven surfaces rendered by impressing an instrument (impresso) and applying plastic bands, additionally fastened by impressing sharp instruments (relief impresso), is a time-consuming technique, requiring a lot of attention. It is therefore no wonder that the technique takes over of applying a layer of clay over a semi-dry surface and then arranging it with fingers – barbotine, since it is simpler and requires less work for the same effect. Current archaeological analyses of technology prove that the process of improvement of pottery forming techniques (leading to craft specialization) above all leads to simplification of procedure, in order to increase the number of vessels produced. Thus the typical assumption of traditional archaeology needs to be questioned, that the "development of culture" may be seen through the "evolution" of shapes and modes of decoration (treatment of surface), inevitably leading from simpler to more complex forms.


2019 ◽  
Vol 25 ◽  
pp. 03008
Author(s):  
Fei Yu

The relationship between technology and design is an eternal discussion as well as controversial topic. In the innovative design of daily-use ceramics, the advancement of technology has brought a lot of room for development in this field. This article will elaborate some effective combination of high-tech technology in daily-use ceramic design in the following four aspects: the combination of electronic technology and daily-use ceramics; the application of double-layer thermal insulation ceramics in the molding process; the analysis of the application of materials such as temperature-sensitive inks and the intervention of new healthy elements such as biochemical materials in the processing technology and surface treatment. Through these aspects to explore the current breakthrough in the design of daily-use ceramics.


1993 ◽  
Vol 44 (3) ◽  
pp. 260-264
Author(s):  
Kenji ISHIJIMA ◽  
Harumi UENO ◽  
Haruhisa MURAKAMI ◽  
Kazuo NAKAJIMA ◽  
Masaru AKIZAWA ◽  
...  

Author(s):  
Ho Shik Lee Et.al

ITO (indium-tin-oxide) is used widely as the anode electrode in organic electroluminescence devices (OLEDs).  Several studies have dealt with the effect of ITO chemical treatment but to the OLEDs performance have not been considered the effect of this treatment. We were present here results regarding these effect.We studies of the effect of surface treatments on the properties of ITO substrate. We were performed chemical treatment with RCA and Aqua regiaof the OELDs. Since we will understand the properties of OELDs, we were performed Fowler-Nordheim tunneling. The buffer layer and ITO surface treatment were performed to increase the efficiency of the OLEDs. As a result, we were obtained conform the surface properties of ITO can be significantly changed by chemical treatment. The oxygen decrease produced by chemical treatment lead to increase of oxygen vacancies. We conformed that the oxygen vacancies role on increasing carrier injection. A study on the cause of improving the performance of the device using the surface treatment and the usingthe buffer layer will be of great help in understanding the relationship between the properties  of the ITO substrate and the organic electroluminescent device.


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